DODGE NEON 1999 Service Repair Manual

Diagnosis Guide
21 - 48 TRANSAXLEPL
DIAGNOSIS AND TESTING (Continued)

Diagnosis Guide
PLTRANSAXLE 21 - 49
DIAGNOSIS AND TESTING (Continued)

Diagnosis Guide
21 - 50 TRANSAXLEPL
DIAGNOSIS AND TESTING (Continued)

Diagnosis Guide
PLTRANSAXLE 21 - 51
DIAGNOSIS AND TESTING (Continued)

ROAD TEST
Prior to performing a road test, check the fluid
level and control cable adjustments.
During the road test, the transaxle should be oper-
ated in each position to check for slipping and any
variation in shifting.
If vehicle operates at high speeds, but has poor
acceleration, the converter's overrunning clutch may
be slipping. If acceleration is normal, but high throt-
tle opening is needed for high speeds, the stator
clutch may have seized.
Observe closely for slipping or engine speed flare-
up. Slipping or flare-up in any gear usually indicates
clutch, band, or overrunning clutch problems. If the
condition is far advanced, an overhaul will probably
be necessary to restore normal operation.
In most cases, the clutch or band that is slipping
can be determined by noting the transaxle operation
in all selector positions and then comparing which
internal units are applied in those positions. The
Elements±in±Use Chart provides a basis for road test
analysis.
The rear clutch is applied in both the D first gear
and 1 first gear positions. Also, the overrunning
clutch is applied in D first gear and the low/reverse
band is applied in 1 first gear position. If the tran-
saxle slips in D range first gear, but does not slip in
1 first gear, the overrunning clutch is slipping. Simi-
larly, if the transaxle slips in any two forward gears,
the rear clutch is slipping.
Using the same procedure, the rear clutch and
front clutch are applied in D third gear. If the tran-
saxle slips in third gear, either the front clutch or the
rear clutch is slipping. By selecting another gear that
does not use one of those units, the unit that is slip-
ping can be determined. If the transaxle also slips in
reverse, the front clutch is slipping. If the transaxle
does not slip in reverse, the rear clutch is slipping.The process of elimination can be used to detect
any unit that slips and to confirm proper operation of
good units. Road testing can usually diagnose slip-
ping units, although the actual cause of the problem
may not be detected. Practically any condition can be
caused by leaking hydraulic circuits or sticking
valves.
Therefore, unless the condition is obvious, the tran-
saxle should never be disassembled until hydraulic
pressure tests have been performed.
HYDRAULIC PRESSURE TESTS
Pressure testing is a very important step in the
diagnostic procedure. These tests usually reveal the
cause of most transaxle problems.
Before performing pressure tests, check fluid level
and condition, as well as control cable adjustments.
Fluid must be at operating temperature (150 to 200
degrees F.).
Install an engine tachometer. Raise vehicle on a
hoist that allows front wheels to turn, and position
tachometer so it can be read.
Disconnect throttle cable and shift cable from tran-
saxle levers so they can be controlled from outside
the vehicle.
Attach 150 psi gauges to ports required for test
being conducted. A 300 psi gauge (C-3293) is required
for reverse pressure test at rear servo.
Test port locations are shown in (Fig. 3).
TEST ONE (SELECTOR IN 1)
(1) Attach gauges to line and low-reverse ports.
(2) Operate engine at 1000 rpm for test.
(3) Move selector lever on transaxle all the way
rearward (1 position).
(4) Read pressures on both gauges as throttle lever
on transaxle is moved from full clockwise position to
full counterclockwise position.
ELEMENTS IN USE AT EACH POSITION OF THE SELECTOR LEVER
21 - 52 TRANSAXLEPL
DIAGNOSIS AND TESTING (Continued)

(5) Line pressure should read 52 to 58 psi with
throttle lever clockwise. Pressure should gradually
increase to 80 to 88 psi.as lever is moved counter-
clockwise.
(6) Low/reverse pressure should read the same as
line pressure, within 3 psi.
(7) This tests pump output, pressure regulation,
and condition of rear clutch and rear servo hydraulic
circuits.
TEST TWO (SELECTOR IN 2)
(1) Attach one gauge to line pressure port, and tee
another gauge into lower cooler line fitting. This will
allow lubrication pressure readings to be taken..
(2) Operate engine at 1000 rpm for test.
(3) Move selector lever on transaxle one detent for-
ward from full rearward position. This is selector 2
position.
(4) Read pressures on both gauges as throttle lever
on transaxle is moved from full clockwise position to
full counterclockwise position.
(5) Line pressure should read 52 to 58 psi with
throttle lever clockwise. Pressure should gradually
increase to 80 to 88 psi. as lever is moved counter-
clockwise.
(6) Lubrication pressure should be 10 to 25 psi
with lever clockwise and 10 to 35 psi with lever at
full counterclockwise.
(7) This tests pump output, pressure regulation,
and condition of rear clutch and lubrication hydraulic
circuits.
TEST THREE (SELECTOR IN D)
(1) Attach gauges to line and kickdown release
ports.
(2) Operate engine at 1600 rpm for test.
Fig. 3 Test Port Locations
Fig. 4 Governor Pressure Tap
PLTRANSAXLE 21 - 53
DIAGNOSIS AND TESTING (Continued)

(3) Move selector lever on transaxle two detents
forward from full rearward position. This is selector
D position.
(4) Read pressures on both gauges as throttle lever
on transaxle is moved from full clockwise to the full
counterclockwise position.
(5) Line pressure should read 52 to 58 psi with
throttle lever clockwise. Pressure should gradually
increase to 80 to 88 psi. as lever is moved counter-
clockwise.
(6) Kickdown release is pressurized only in direct
drive and should be same as line pressure within 3
psi, up to kickdown point.
(7) This tests pump output, pressure regulation,
and condition of rear clutch, front clutch, and
hydraulic circuits.
TEST FOUR (SELECTOR IN REVERSE)
(1) Attach 300 psi gauge to low-reverse port.
(2) Operate engine at 1600 rpm for test.
(3) Move selector lever on transaxle four detents
forward from full rearward position. This is selector
R position.
(4) Low/reverse pressure should read 180 to 220
psi with throttle lever clockwise. Pressure should
gradually increase to 260 to 300 psi. as lever is
moved counterclockwise.
(5) This tests pump output, pressure regulation,
and condition of front clutch and rear servo hydraulic
circuits.
(6) Move selector lever on transaxle to D position
to check that low/reverse pressure drops to zero.
(7) This tests for leakage into rear servo, due to
case porosity, which can cause reverse band burn out.
TEST RESULT INDICATIONS
(1) If proper line pressure, minimum to maximum,
is found in any one test, the pump and pressure reg-
ulator are working properly.
(2) Low pressure in D, 1, and 2 but correct pres-
sure in R, indicates rear clutch circuit leakage.
(3) Low pressure in D and R, but correct pressure
in 1 indicates front clutch circuit leakage.
(4) Low pressure in R and 1, but correct pressure
in 2 indicates rear servo circuit leakage.
(5) Low line pressure in all positions indicates a
defective pump, a clogged filter, or a stuck pressure
regulator valve.
GOVERNOR PRESSURE
Test only if transaxle shifts at wrong vehicle
speeds when throttle cable is correctly adjusted.
(1) Connect a 0-150 psi pressure gauge to governor
pressure take-off point. It is located at lower right
side of case, below differential cover.
(2) Operate transaxle in third gear to read pres-
sures. The governor pressure should respondsmoothly to changes in mph and should return to 0
to 3 psi when vehicle is stopped. High pressure
(above 3 psi) at standstill will prevent the transaxle
from downshifting.
THROTTLE PRESSURE
No gauge port is provided for throttle pressure.
Incorrect throttle pressure should be suspected if
part throttle upshift speeds are either delayed or
occur too early in relation to vehicle speed. Engine
runaway on shifts can also be an indicator of low
throttle pressure setting, or misadjusted throttle
cable.
In no case should throttle pressure be adjusted
until the transaxle throttle cable adjustment has
been verified to be correct.
CLUTCH AND SERVO AIR PRESSURE TESTS
A no±drive condition might exist even with correct
fluid pressure, because of inoperative clutches or
bands. The inoperative units, clutches, bands, and
servos can be located through a series of tests. This
is done by substituting air pressure for fluid pressure
(Fig. 5).
The front and rear clutches, kickdown servo, and
low/reverse servo can be tested by applying air pres-
sure to their respective passages. To make air pres-
sure tests, proceed as follows:
NOTE: Compressed air supply must be free of all
dirt and moisture. Use a pressure of 30 psi.
Remove oil pan and valve body. Refer to Valve
Body for removal procedure.
FRONT CLUTCH
Apply air pressure to front clutch apply passage
and listen for a dull thud, which indicates that front
clutch is operating. Hold air pressure on for a few
seconds and inspect system for excessive oil leaks.
REAR CLUTCH
Apply air pressure to rear clutch apply passage
and listen for a dull thud, which indicates that rear
clutch is operating. Also, inspect for excessive oil
leaks. If a dull thud cannot be heard in the clutches,
place finger tips on clutch housing and again apply
air pressure. Movement of piston can be felt as the
clutch is applied.
KICKDOWN SERVO (FRONT)
Direct air pressure into KICKDOWN SERVO ON
passage. Operation of servo is indicated by a tighten-
ing of front band. Spring tension on servo piston
should release the band.
21 - 54 TRANSAXLEPL
DIAGNOSIS AND TESTING (Continued)

LOW AND REVERSE SERVO (REAR)
Direct air pressure into LOW/REVERSE SERVO
APPLY passage. Operation of servo is indicated by a
tightening of rear band. Spring tension on servo pis-
ton should release the band.
If clutches and servos operate properly, no upshift
indicates that a malfunction exists in the valve body.
FLUID LEAKAGE-TRANSAXLE TORQUE
CONVERTER HOUSING AREA
(1) Check for source of leakage.
(2) Since fluid leakage near the torque converter
area may be from an engine oil leak, the area should
be checked closely. Factory fill fluid is dyed red and,
therefore, can be distinguished from engine oil.
(3) Prior to removing the transaxle, perform the
following checks:
(4) When leakage is determined to originate from
the transaxle, check fluid level prior to removal of
the transaxle and torque converter.
(5) High oil level can result in oil leakage out the
vent in the dipstick. If the fluid level is high, adjust
to proper level.
(6) After performing this operation, inspect for
leakage. If a leak persists, perform the followingoperation on the vehicle. This will determine if the
torque converter or transaxle is leaking.
TORQUE CONVERTER LEAKAGE
Possible sources of torque converter leakage are:
²Torque converter weld leaks at the outside diam-
eter (peripheral) weld
²Torque converter hub weld
²Torque converter impeller shell cracked adjacent
to hub
²At drive lug welds
NOTE: Hub weld is inside and not visible. Do not
attempt to repair. Replace torque converter.
INTERLOCK SYSTEM OPERATION CHECK
(1) Place shifter in PARK, the ignition switch
should rotate freely from OFF to LOCK position.
When the shifter is moved to the DRIVE position,
the ignition switch should not rotate from OFF to
LOCK.
(2) Moving shifter out of PARK should be possible
only when ignition switch is in the OFF or the RUN
position. Movement of the shifter from the PARK
Fig. 5 Air Pressure Tests
PLTRANSAXLE 21 - 55
DIAGNOSIS AND TESTING (Continued)

position should not be possible when the ignition
switch is in the LOCK or the ACCESSORY position.
(3) If the interlock system, operates in any way
other than as described above, repair of the interlock
system is required. See Adjustment and Repair pro-
cedures in this section for the required procedures.
SERVICE PROCEDURES
FLUID AND FILTER CHANGE
When the factory fill fluid is changed, only fluids
labeled MOPARtATF PLUS 3 (Automatic Transmis-
sion fluid) Type 7176 should be used.
If the transaxle is disassembled for any reason, the
fluid and filter should be changed.
30,000 MILE TRANSAXLE OIL CHANGE
When a vehicle attains 30,000 miles on its odome-
ter it is recommended that the transaxle oil be
changed. To change the oil, use the procedure that
follows:
It is recommended that a transaxle fluid exchanger
(ATF 2000+ or equivalent) be used to replace the
used fluid in the transaxle. If a fluid exchanger is not
available use a fluid suction pump (Vaculayor equiv-
alent) to draw the fluid out of the dipstick tube. If a
fluid suction pump is not available remove the oil
pan and drain the fluid.
CAUTION: Chrysler Corporation does not recom-
mend using any fluid exchanger that introduces
additives into the transaxle.
TRANSAXLE FLUID EXCHANGER METHOD
(1) To perform the transaxle fluid exchange, the
transaxle must be at operating temperature. Drive
the vehicle till it reaches full operating temperature.
(2) Verify that the fill tank on the transaxle fluid
exchanger (ATF 2000+ or equivalent) is clean and
dry.
(3) Fill the tank to the recommended fill capacity
with Mopar ATF Plus 3 Type 7176.
(4) Hookup the vehicle to the machine following
the manufacturers instructions. Perform the
exchange procedure following the instructions pro-
vided with the machine.
(5) Once machine has completed the fluid
exchange. Check the fluid level and condition and fill
to proper level with Mopar ATF Plus 3 Type 7176.
NOTE: Verify that the transaxle cooler lines are
tightened to proper specifications. Cooler line
torque specification is 2 N²m (18 in. lbs.).DIPSTICK TUBE FLUID SUCTION METHOD
(1) When performing the fluid suction method,
make sure the transaxle is at full operating temper-
ature.
(2) To perform the dipstick tube fluid suction
method, use a suitable fluid suction device (Vaculay
or equivalent).
(3) Insert the fluid suction line into the dipstick
tube.
NOTE: Verify that the suction line is inserted to the
lowest point of the transaxle oil pan. This will
ensure complete evacuation of the fluid in the pan.
(4) Follow the manufacturers recommended proce-
dure and evacuate the fluid from the transaxle.
(5) Remove the suction line from the dipstick tube.
(6) Add 4 Quarts of Mopar ATF Plus 3 Type 7176
transaxle fluid.
(7) Start the engine and allow it to idle for a min-
imum of one minute. With the parking brake applied,
press your foot on the service brake and cycle the
transaxle from park to all gear positions ending in
neutral or park.
(8) Check the transaxle fluid level and add an
appropriate amount to bring the transaxle fluid level
to 3mm (1/8 in.) below the ADD mark on the dip-
stick.
(9) Recheck the fluid level after the transaxle is at
normal operating temperature. The level should be in
the HOT range.
TRANSAXLE OIL PAN DROP METHOD
This procedure involves removing the transaxle oil
pan to drain the transaxle fluid.
(1) Bring the vehicle up to normal operating tem-
perature. Drive the vehicle a minimum of 10 miles.
(2) Raise the vehicle on the hoist.
(3) Loosen the transaxle oil pan and drain the
fluid into a suitable container.
(4) Remove the pan and clean all sealant from the
pan and transaxle mating surfaces. Clean the mag-
net and the inside of the pan.
(5) Apply a 1/8 inch bead of Mopar RTV Sealant to
the mounting flange of the transaxle oil pan. Apply
RTV Sealant to the underside of the attaching bolts.
Attach the oil pan to the transaxle. Tighten the bolts
to 19 N²m (165 in. lbs.).
(6) Lower the vehicle and add 4 Quarts of Mopar
ATF Plus 3 Type 7176 transaxle fluid.
(7) Start the engine and allow it to idle for a min-
imum of one minute. With the parking brake applied,
press your foot on the service brake and cycle the
transaxle from park to all gear positions ending in
neutral or park.
(8) Check the transaxle fluid level and add an
appropriate amount to bring the transaxle fluid level
21 - 56 TRANSAXLEPL
DIAGNOSIS AND TESTING (Continued)

to 3mm (1/8 in.) below the ADD mark on the dip-
stick.
(9) Recheck the fluid level after the transaxle is at
normal operating temperature. The level should be in
the HOT range. Drive the vehicle a minimum of 10
miles.
(10) Raise the vehicle on the hoist.
(11) Check for leaks around the transaxle oil pan
sealing surfaces.
(12) Recheck the fluid level. The level should be in
the HOT range.
SEVERE USAGE SERVICE
If the vehicle exhibits any of the following symp-
toms, it is recommended that the transaxle oil and
filter be replaced.
²Transaxle oil discolored
²Transaxle oil has high mileage
²Oil feels grimy when rubbed between fingertips
²Poor shift quality
²Delayed gear engagement
²Vehicle shudder between shifts
TRANSAXLE OIL AND FILTER REPLACEMENT
This procedure involves changing the transaxle
fluid and filter, driving the vehicle for 10 miles and
changing the transaxle fluid a second time.
(1) Bring the vehicle up to normal operating tem-
perature. Drive the vehicle a minimum of 10 miles.
(2) Raise the vehicle on the hoist.
(3) Loosen the transaxle oil pan and drain the
fluid into a suitable container.
(4) Remove the pan and clean all sealant from the
pan and transaxle mating surfaces. Clean the mag-
net and the inside of the pan.
(5) Separate the filter and O-ring from the valve
body. Inspect the O-ring for cuts or improper instal-
lation. This could lead to delayed garage shifts.
(6) Install a new filter. Replace the O-ring as nec-
essary.
(7) Apply a 1/8 inch bead of Mopar RTV Sealant to
the mounting flange of the transaxle oil pan. Apply
RTV Sealant to the underside of the attaching bolts.
Attach the oil pan to the transaxle. Tighten the bolts
to 19 N²m (165 in. lbs.).
(8) Lower the vehicle and add 4 Quarts of Mopar
ATF Plus 3 Type 7176 transaxle fluid.
(9) Start the engine and allow it to idle for a min-
imum of one minute. With the parking brake applied,
press your foot on the service brake and cycle the
transaxle from park to all gear positions ending in
neutral or park.
(10) Check the transaxle fluid level and add an
appropriate amount to bring the transaxle fluid level
to 3mm (1/8 in.) below the ADD mark on the dip-
stick.(11) Recheck the fluid level after the transaxle is
at normal operating temperature. The level should be
in the HOT range. Drive the vehicle a minimum of
10 miles.
(12) Raise the vehicle on the hoist.
(13) Remove the pan and clean all sealant from
the pan and transaxle mating surfaces. Clean the
magnet and the inside of the pan.
(14) Separate the filter from the valve body to
allow additional fluid to drain from the transaxle.
Inspect the filter O-ring for any damage and replace
as necessary.
(15) After the transaxle has stopped draining,
reinstall the filter and O-ring.
(16) Apply a 1/8 inch bead of Mopar RTV Sealant
to the mounting flange of the transaxle oil pan.
Apply RTV Sealant to the underside of the attaching
bolts. Attach the oil pan to the transaxle. Tighten the
bolts to 19 N²m (165 in. lbs.).
(17) Lower the vehicle and add 4 Quarts of Mopar
ATF Plus 3 Type 7176 transaxle fluid.
(18) Start the engine and allow it to idle for a min-
imum of one minute. With the parking brake applied,
press your foot on the service brake and cycle the
transaxle from park to all gear positions ending in
neutral or park.
(19) Check the transaxle fluid level and add an
appropriate amount to bring the transaxle fluid level
to 3mm (1/8 in.) below the ADD mark on the dip-
stick.
(20) Recheck the fluid level after the transaxle is
at normal operating temperature. The level should be
in the HOT range.
FLUID DRAIN AND REFILL
(1) Raise vehicle on a hoist (See Group 0, Lubrica-
tion). Place a drain container, with a large opening,
under transaxle oil pan.
(2) Loosen pan bolts and tap the pan at one corner
to break it loose allowing fluid to drain, then remove
the oil pan.
(3) Install a new filter and gasket on bottom of the
valve body and tighten retaining screws to 5 N´m (40
inch-pounds).
(4) Clean the oil pan and magnet. Reinstall pan
using new sealant. Tighten oil pan bolts to 19 N´m
(165 in. lbs.).
(5) Pour four quarts of Mopar ATF PLUS 3 (Auto-
matic Transmission Fluid) type 7176 into the tran-
saxle filler tube.
(6) Start engine and allow to idle for at least one
minute. Then, with parking and service brakes
applied, move selector lever momentarily to each
position, ending in the PARK or NEUTRAL position.
(7) Add sufficient fluid to bring level to 1/8 inch
below the ADD mark.
PLTRANSAXLE 21 - 57
SERVICE PROCEDURES (Continued)